Transliteration systems

This note is still a TODO. Transliteration is learning learning a function to map strings in one character set to strings in another character set. The basic example is in multilingual applications, where it is needed to have the same string written in different languages. The goal is to develop a probabilistic model that can map strings from input vocabulary $\Sigma$ to an output vocabulary $\Omega$. We will extend the concepts presented in Automi e Regexp for Finite state automata to a weighted version. You will also need knowledge from Descrizione linguaggio for definitions of alphabets and strings, Kleene Star operations. ...

4 min Â· Xuanqiang 'Angelo' Huang

Introduction to Natural Language Processing

The landscape of NLP was very different in the beginning of the field. “But it must be recognized that the notion ‘probability of a sentence’ is an entirely useless one, under any known interpretation of this term 1968 p 53. Noam Chomsky. Probability was not seen very well (Chomsky has said many wrong things indeed), and linguists were considered useless. Recently deep learning and computational papers are ubiquitous in major conferences in linguistics, e.g. ACL. ...

2 min Â· Xuanqiang 'Angelo' Huang

Probabilistic Parsing

Language Constituents A constituent is a word or a group of words that function as a single unit within a hierarchical structure This is because there is a lot of evidence pointing towards an hierarchical organization of human language. Example of constituents Let’s have some examples: John speaks [Spanish] fluently John speaks [Spanish and French] fluently Mary programs the homework [in the ETH computer laboratory] Mary programs the homework [in the laboratory] ...

5 min Â· Xuanqiang 'Angelo' Huang

Softmax Function

Softmax is one of the most important functions for neural networks. It also has some interesting properties that we list here. This function is part of The Exponential Family, one can also see that the sigmoid function is a particular case of this softmax, just two variables. Sometimes this could be seen as a relaxation of the action potential inspired by neuroscience (See The Neuron for a little bit more about neurons). This is because we need differentiable, for gradient descent. The action potential is an all or nothing thing. ...

3 min Â· Xuanqiang 'Angelo' Huang